Production of loop pile textiles



Sept. 6, 1966 c. R. KOLLER 3,271,216

PRODUCTION OF LOOP FILE TEXTILES Filed Jan. 22, 1965 LOOP-SHAPED FIBROUSMEMBER (YARN).

FILAIIENTARY STRUCTURE (FIBER).

BINDER PARTICLE.

BINDER ADHESIVE LAYER FIBROUS NENBERS WITH BINDER REMOVED. *II

0 {3 (II ADHESIVE.

RII'IIIII I I BACKING.

BACKED ARTICLE WITH BINDER REIIDVED INVENTOR CHARLES RICHARD KOLLER (PMQ2 V ATTORNEY ted States Patent This invention relates to loop piletextiles and to processes for the manufacture thereof.

An object of this invention is to provide both selfsupporting sheets asWell as backed articles having a loop pile configuration in at least oneface, whereby the sheets and backed articles exhibit a combination ofimproved properties over existing pile structures and, in addition,provide a range of different aesthetics not possible in pile structureswherein the surface is defined solely by cut filament ends. A furtherobject includes n-ovel processes for the manufacture of said loop pileself-supporting sheets and backed articles. More specifically it is anobject of this invention to provide novel pile fabrics having bettertuft adhesion, as well as less grinning. Other objects will be apparentfrom the description of the invention given below.

This application is a continuation-in-part of US. application, SerialNo. 787,662 filed January 19, 1959, now US. Patent No. 3,085,922.

This invention provides a porous self-supporting sheet material havingtwo opposing faces and comprising a multitude of loop-shaped fibrousmembers. Each of the fibrous members is in turn composed of a pluralityof filamentary structures or fibers which are aligned generally in thesame direction throughout the member and which overlap and areinterconnected at a plurality of spaced points throughout the threedimensions of the sheet material. One of the opposing faces is definedby a series of pairs of cut ends of the loop-shaped fibrous members,that is, for each fibrous member both of the cut ends will serve todefine that face. The other opposing face is defined by a plurality ofthe closed curved portions of the loop-shaped fibrous members. The sheetmaterial is further characterized as having a fiber density below about25 lbs./ft. In a preferred embodiment, the porous self-supporting sheetmaterial will have at least 65% by weight of the filamentary structuresextending from one cut end of the loop-shaped fibrous member to theother cut end. The invention also provides a textile article such as apile fabric comprising a backing layer and a pile layer, the pile layerconstituting a porous selfsupporting sheet material as described above.In this case the loops will be exposed and upstanding such that the cutends of the fibrous members will be attached to the backing. Theinvention also provides such backed pile layers from which theinterconnections have been removed.

According to the process of the invention, the foregoing materials areprepared by first providing one or more fibrous bundles each composed ofa plurality of contorted filamentary structures which are overlappingand intercontacting throughout the three dimensions of the bundle. Thefilamentary structures also are aligned generally in the same directionthroughout the bundle. Thereafter the bundles are pleated in sinusoidalconfiguration to provide a body having a fiber density below 25 lbs./ft.wherein filamentary structures of adjacent pleats of the bundles overlapone another, and wherein the body has two opposing faces defined byclosed curved portions of the bundles. At least a major proportion ofthe filamentary structures are then interconnected at a plurality ofspaced points along their lengths throughout the three dimensions ofsaid body while maintained in sinusoidal configuration, and finally thebody is sectioned in a plane intermediate the two opposing faces.Preferably the body will be so sectioned or sliced as to provide twosubstantially equal halves, eg by a median planar slice parallel to bothopposing faces of the body. Both resulting sheet materials will thus beof nearly equal dimension and will have one face defined by the closedloops of fibrous members, i.e. portions of the sectioned bundles, andthe other face defined by cut filament ends.

As indicated the fibrous bundles to be pleated, interconnected andsectioned in accordance with this invention are composed of filamentarystructures or fibers which are aligned generally in the same directionthroughout the bundle. Similarly the resulting sheet material will becomposed of fibrous members or severed sections of the bundles whichalso are aligned generally in the same direction throughout the member.In either case aligned refers to the characteristic that although thefilamentary structures have a contorted configuration between their endsand are curved in a loop, many nevertheless extend from one cut end ofthe fibrous bundle or member to the other cut end. In the case of asheet material, at least 65% by number of the filaments should extendfrom one cut end to the other.

If the fibrous members or bundles are so severed to remove the loopconfiguration, at least 65 by number of the filamentary structurestherein are aligned generally in a direction between about 20 and abouttransverse to at least one of the two resulting faces but preferably inthe same direction. To ascertain if the filamentary structures of anyfibrous bundle or member are aligned generally in the same directiontherein, it is helpful to visualize that the bundle or member has beenso severed to remove the loop and that all portions of individualfilamentary structures are circumscribed by an imaginary cylinder, thefilamentary structure ends terminating in the bases of the cylinder. Theindividual filaments may be said to have a direction corresponding tothe direction of the axis of the cylinder. The filamentary structuresthen can be said to be aligned generally in the same direction when theaxes of the circumscribing cylinders are aligned generally in the samedirection.

V The textile articles of this invention are useful per se in the formof self-supporting sheet material or they may be further processed byattaching the face of the sheet material containing the cut filamentends to a backing layer. After applying a backing any binder compositionemployed in the pile layer to interconnect the filamentary members maybe left in the final textile article or may be removed, depending uponthe use intended and the properties desired in the final article.

The invention will be further described in the accompanying drawings.FIGURE 1 illustrates the self-supporting sheet material of thisinvention. FIGURE 2 illustrates the backed article of this inventionwith the binder still present in the pile layer. FIGURE 3 illustnatesthe backed article of this invention after removal of binder from thepile layer.

A preferred method for preparing the novel sheet material illustrated inFIGURE 1 involves first assembling at least one, preferably several,groups of highly crimped continuous filaments wherein the individualfilaments are aligned in the same direction and wherein they overlap oneanother in the fibrous bundle. The bundles are assembled in a moldhaving two open faces and which is further provided with a series ofbars for pleating. Each of the fibrous bundles is pleated by passingover and under the bars to form a series of sinusoidal configurations.Thus each bundle will form a repeating S shaped pattern or meanderingpath, the closed curved loops of which define opposite surfaces. Theportions of such bundles between the loops are adjacent one another insubstantially parallel arrangement with fibers of one portionoverlapping and contacting fibers of another portion. The bundles arethus arranged so that the closed loops point to the open faces of themold, each bundle being pleated behind the next succeeding bundle in themold. The bars are arranged so that the pleats may be held mechanicallyduring application of a binder. After closing the mold, the assembly ofpleated fibrous bundles is impregnated by filling the mold with liquidbinder composition through an entry pipe. The mold is then drained ofexcess binder from the fibrous assembly through an exit pipe Whilemaintaining the pleated configuration. The mold is then heated to driveolf excess liquid and solidify the binder at a plurality of spacedpoints along the lengths of the filaments. After bonding the filamentstogether to provide interconnections of binder composition the sides ofthe mold and the pleating bars are removed to leave .an assembly ofbonded pleated filaments. A knife or other cutting means is then used toslice approximately half way between the two faces of the bondedfilamentary assembly, essentially in a plane parallel to the two facesand transversely to the filaments. As a result two self-supportingsheets are produced, each sheet being characterized by having one facedefined by each of the cut ends of fibrous members, sectioned portionsof the bundle, and the other face being defined by closed loops of thefibrous members. These sheets are self-supporting by virtue of the factthat the pleated filaments constituting the fibrous members areinterconnected at a series of spaced points with sufficient binder toprevent the filaments from falling out of the sheet when the sheet ishandled, processed or bent around a mandrel. Then, if desired, the sheetmaterial may be attached to a backing such as a layer of burlap fabricby placing a layer of suitable adhesive on one face of the backing andpressing the face of the sheet containing the cut filament ends into theadhesive, forming a backed textile.

article, the pile surface of which is composed of closed filament loops.

In a preferred embodiment the fibrous members whose ends define one faceof the self-supporting sheet material of this invention are upstandingin relation to that face such that the portion of the members adjacentthe cut ends intersects the face at an angle of at least 30 and usuallyof at least 50.

An alternative process may be employed in which the fibrous bundles arepartially bonded and/ or stiffened with binder prior to pleating. Afterpleating the pleating bars, or slots, can be removed and the assemblyretains its pleatedarrangement because of its stifiness. This pleatedassembly may then be further impregnated with binder to obtain a morecompletely bonded pleated assembly. The dimensions of the fibrousbundles are not critical so long as the length is adequate to permit theformation of a series of pleats. In cross section the bundle may becircular, oval, rectangular, etc. For certain purposes a single widebundle may be employed to produce a sheet material of suitable surfacearea although the use of a plurality of bundles is preferred. For mostapplications a sheet material having a pile height below 2 inches willbe adequate.

A full description of the filamentary materials employed in accordancewith this invention for the production of styled pile fabrics is setforth in the above mentioned Koller US. application, Serial No. 787,662.These materials are of a porous character and have a plurality ofcontorted, e.g. crimped, filamentary structures which overlap, arealigned generally in the same direction, are intercontacting orinterconnected throughout the three dimensions of the material and thematerial has a fiber density below 25 lbs/ft. preferably below 8 lbs/ft.Although a description of these materials including definitions of theterms used in connection therewith is fully set forth in the aboveKoller application, the disclosure of which is specifically incorporatedherein by reference, they will be briefly mentioned herein. By contortedit is meant that the profile (i.e. side elevation) of an individualfilament is irregular (i.e. not straight) when the filament is viewedfrom at least one side. In addition to being contorted, it is necessarythat such filamentary structures overlap adjacent structures throughoutthe three dimensions of the article. By the term overlap is meant thatin at least one view a filamentary structure crosses over, with orwithout touching or attachments, an adjacent filamentary structure.Furthermore, it is critical to such structures that the contortion andoverlapping of the filamentary structures do coact or are allowed tocoact with one another. By coact is meant that the contortion andrelative placement of the filamentary structures are such that theyassist one another in producing .and maintaining the claimed structuresboth with respect to the general alignment of the filamentary structuresand their spacing with respect to each other to achieve the desirabledensities contemplated.

The initial fibrous bundles may be in any of a variety of forms, forexample, carded webs of substantially aligned staple fibers or bodies ofsubstantially aligned filamentary structures prepared from a warp ofsliver, top, roping, roving, tow stuffer box crimped tow, steam bulkedtow, steam crimped continuous filament yarn, gear crimped continuousfilament yarn, twist set-back twisted continuous filament yarn, knifeedge crimped continuous filament yarn, two-component bulky continuousfilament yarn, spun yarns, and many others. The above procedure may thenbe followed to prepare the pleated arrangement of such bundles for usein this invention.

In preparing a fibrous bundle of contorted fibers a wide variety ofpolymeric compositions may be employed. Typical of the fibers andfilaments which may be employed are those made of polyamides, such aspoly(hexamethylene adipamide), poly(meta-phenylene isophthalamide),poly(hexamethylene sebacamide), p'olycaproamide, copolyamides andirradiation grafted polyamides, polyesters and copolyesters such ascondensation products of ethylene glycol with terephthalic acid,ethylene glycol with a /10 mixture of terephthalic/isophthalic acids,ethylene glycol with a 98/2 mixture of terephthalic/S- (sodiumsulfo)-isophthalic acids, and trans-p-hexahydroxylylene glycol withterephthalic acid, self-elongating ethyleneterephthalate polymers,polyacrylonitrile, copolymers of acrylonitrile with other monomers suchas vinyl acetate, vinyl chloride, methyl acrylate, vinyl pyridine,sodium styrene sulfonate, terpolymers of acrylonitrile/ methylacrylate/sodium styrene sulfonate made in accordance with US. Patent 2,837,501,vinyl and vinylidene polymers and copolymers, polycarbonate-s,polyacetals, polyethers, polyurethanes such as segmented polymersdescribed in US. Patents 2,957,852 and 2,929,804, polyesteramides,polysulfonamides, polyethylenes, polypropylenes, fiuorinated and/orchlorinated ethylene polymers and copolymers (e.g.,polytetrafluoroethylene, polytrifluorochloroethylenes), cellulosederivatives, such as cellulose acetate, cellulose triacetate, compositefilaments such as, for example, a sheath of polyamide around a core ofpolyester as described in the U8. Patent 3,038,236, and self-crimpedcomposite filaments, such as two acrylonitrile polymers differing inionizable group content cospun side by side as described in US. Patent3,038,237, regenerated cellulose, cotton, wool, glass, metal, ceramicand the like. Blends of two or more synthetic or natural fibers may beused as well as blends of synthetic and natural. Other fibers such assilk, animal fibers such as mohair, angora, vicuna are also suitable.

The self-supporting material may be prepared from a wide variety offorms .of fibers and filaments having any of the above-mentionedcompositions, such as, for example, continuous monofilaments, continuousmultifilaments, carded webs, warp, sliver, top, roping, roving tow,

bulked tow, bulked continuous filament yarn, spun yarn, batts, felts,papers and other non-woven webs, and the like. The fibers and filamentsused as raw material may be either crimped or uncrimped, bulked orunbulked, drawn or undr-awn or twisted or untwisted. The denier of thefilaments is not critical and may vary from about 0.5 to about 50 denieror even higher.

The use of a binder is preferred to interconnect the filamentarystructures at a plurality of points along their length. Depending uponthe use desired, these may be either soluble or insoluble, and may beeither thermoplastic in nature or may be thermosetting for subsequentreaction with a curing agent to form a cured polymer. By binder is meantthe additional material used to attach the filaments to each other.Normally these materials will be used in an amount of -at least about0.5%

by weight based on the filamentary structures. If it is desired toremove the binder after attaching to a backing to the traversely slicedsheet material a soluble binder will be employed which may be eitherorganic-soluble or Water-soluble. Suitable organic-soluble bindersinclude natural rubber or synthetic elastomers (e.g., chloroprene,butadienestyrene copolymers, butadiene-acrylonitrile copolymers), whichmay be used in the form of a latex dispersions or emulsion .or in theform of a solution, vinyl acetate polymers and copolymers, acrylicpolymers and copolymers such as ethyl acrylate, methyl acrylate, butylacrylate, methyl methacrylate, acrylic acid/acrylic and methacrylicester copolymers, cellulose nitrate, cellulose acetate, cellulosetriacetate, polyester resins such as ethylene terephthal-ate/ ethyleneisophthalate copolymers, polyurethanes such as the polymer frompiperazine and ethylene bis-chloroformate, polyamide polymers, andcopolymers, methoxymethyl p'olyamides, vinyl chloride polymers andcopolymers such as vinyl chloride/vinylidene chloride copolymer latices.Alcohol soluble polyamide resins are also suitable organic-solublebinders. Suitable watersoluble binders include materials such aspolyvinyl alcohol, sodium alginate, acrylic acid polymers andcopolym-ers such as polyacrylic acid, carboxymethyl cellulose,hydroxyethyl cellulose, dextrins, animal glue, soybean glue and sodiumsilicate. Suitable binders which are insoluble in organic solventsinclude polytetrafluoroethylene and ureaformaldehyde resin latices.

Additional suitable binder compositions include chlorosulfonatedpolyethylene; butyl rubbers, such as isobutylene/isoprene copolymers;polyhydrocarbons, such as polyethylene, polypropylene and the like andcopolymers thereof; high molecular Weight polyethylene glycols soldunder the trade name of Polyox; epoxide resins, such as the diepoxide ofbisphenols and glycols; polystyrene; alkyd resins, such as polyesters ofglycerol with phthalic or maleic acid; polyester resins such as frompropylene glycol-maleic anhydride-styrene; phenol-formaldehyde resins;resorcinol-formaldehyde resins; polyvinyl acetals, such as polyvinylbutyral and polyvinyl formal; polyvinyl ethers, such as polyvinylisobutyl ether; starch, zein, casein, gelatine, methyl cellulose, ethylcellulose, poly-vinyl fluoride, natural gums, polyisobutylene, shellac,terpene resins and rosin soaps. Segmented poymers, such as spandexpolymers, polyether amides, polyether urethanes (e.g. those in U.S.2,929,800) and polyester/urethanes are also suitable.

The adhesives which may be used when applying the backing are varied. Byadhesive or glue is meant the material used to cause the filamentarystructures and sheet materials to adhere to the backing or is meant thematerial used to constitute the backing. Illustrative adhesives are:chloroprene rubber, elastomeric foams and sponges, butadiene-styrenerubber, polyvinyl chloride resin (e.g. those in combination with eithera polymeric plasticizer or a monomeric plasticizer curable afterapplication of the adhesive), polyurethane resins, polyamide copolymerof hexamethylene diamine and adipic and sebacic acids, casein resin, andepoxy resins such as the diepoxide of 2,2-bis(parahydroxyphenyl)propane. Illustrative backings are: woven fabrics such as burlap,canvas, and nylon scrim fabrics, knit fabrics such as nylon t-ricot,nonwoven fabrics such as polyethylene or polypropylene fiber webs, resinbonded polyethylene terephthalate fiber webs, papers of cellulosicand/or synthetic fibers, paper felts such as asphalt impregnatedcellulose, elastomeric foams and sponges, plastic films such as frompolyethylene terephthalate, polypropylene and polyvinyl chloridepolymers, metal foils and rigid sheets such as fiber glass reinforcedpolyester resins, metals, ceramics and Wood, elastic, stretchable orshrinkable fabrics and films, and the like.

The pile fiber density or simply fiber density reported in pounds percubic foot is a measure of the density of the fibers in the pile layerof the specimen from which the binder has been removed, or in otherwords the density of the shearable fiber above the adhesive line. Thepile fiber density is calculated by dividing the pile weight of thefibers in the pile layer by the volume these fibers occupy. This volumeis determined by multiplying the average width by the average length ofthe conditioned specimen by the pile height of the sheared fibers, andthen applying suitable conversion factors to obtain the volume in unitsof cubic feet.

One advantage of this invention is that it provides textile articlessuch as pile fabrics having for some purposes superior aesthetics incomparison with previously known pile fabrics having a cut pile surface.Thus the pile fabrics described herein provide more luxuriousness andflexibility of styling when prepared in the form of carpets. The textilearticles of this invention also have superior compressional propertiesthan those made by weaving and tufting. In addition, pile fabricsdescribed herein possess better tuft adhesion than conventional looppile fabrics in that no chain reaction occurs on pulling out one loop asin a conventional woven or tufted loop pile carpet. Still further, thepile fabrics described herein exhibit less grinning and better coverthan conventional loop pile carpets when bent over a curved surface suchas a stair.

The self-supporting sheets and textile articles of this invention areuseful in the form of floor coverings, such as carpets and tiles,upholstery fabrics, furs and fleeces, garment interliners, cushions andmattresses, pile fabrics, fibrous laminated structures, sponges, dustmops, air and dust filters, cleaning cloths, railroad car journal boxlubricator pads and the like.

The following examples illustrate specific embodiments of this inventionbut are not intended. to limit the scope of the invention.

Example I The filaments used are in the form of continuous filamentpolyhexamethylene adipamide yarns (3700 denier, 204 filaments, 0.5 Ztwist and tril obal cross section). These yarns are first bulked Withsteam under the condition disclosed in Example 2, Table III of BelgianPatent 573,230. Approximately 42 ends of this bulked yarn are alignedtogether in the same direction to form a warp or bundle about 5 incheswide Which is sprayed with a 10% by weight solution of a polyamidebinder in a /20 alcohol/ water mixture by volume. This polyamide binderis an alcohol soluble terpolymer formed by condensing togethercaprolactam, hexamethylene diamine, adipic acid and sebacic acid suchthat there are substantially equal proportions of polycaproamide,polyhexamethylene adipamide and polyhexamethylene sebacamide in theterpolymer. The sprayed yarn warp is allowed to air dry to harden thebinder and bond the yarns together. This warp of yarns is then pleatedback and forth over 2-inch Wide metal slats to form a pleated assemblyof yarns 5" wide x 14" long x 2 thick with the loops of yarns in the topand bottom faces (5" x 14" face). The metal slats are removed frombetween the pleats by pulling them out fro-m the side of the pleatedassembly which is sufiiciently stiif to maintain its pleatedarrangement.

This assembly is placed in a perforated metal mold and immersed in a 5%solution of the above described polyamide terpolymer binder inalcohol/water (80/20 by vol.). The mold is removed, excess bindersolution allowed to drain and the assembly heated. at 120 C. to hardenthe binder. The mold is removed and there is obtained a bonded pleatedfiber assembly having a fiber density of about 4.5 1bs./ft. and bindercontent of 7% on the weight of the fiber.

This assembly is sliced transversely to the fiber direction with ahorizontal band knife slicer in a plane parallel with the top and bottompleated surfaces (5" x 14 faces).

There are obtained two porous self-supporting sheets of bonded fiberswith one face consisting of cut ends of yarns and the opposite faceconsisting of yarn loops. This sheet can be wrapped with its cut facearound a small diameter mandrel without splitting or loss of fiber. Theporous self-supporting sheet is useful as a scrubbing pad.

Example 11 A porous self-supporting bonded fiber sheet approximately 4"wide x 14 long x A" thick prepared as described in Example I is attachedto a backing fabric by embedding the face of the sliced sheet consistingof cut ends of yarn in a layer of rubber adhesive coated onto one faceof a burlap fabric. This assembly is held together under light pressurewhile being heated at 822 C. to harden the adhesive and bond the cutends of the yarns to the burlap backing. This backed structure is thenwashed in a solvent of 80 parts alcohol and 20 parts by (a) providingone or more fibrous bundles each composed of a plurality of contortedfilamentary structures which are overlapping and intercontactingthroughout the three dimensions of the bundle, said filamentarystructures being aligned generally in the same direction throughout thebundle,

(b) pleating said bundles in siusoidal configuration to provide a bodyhaving a fiber density below 25 'lbs./ft. wherein filamentary structuresof adjacent pleats of the bundles overlap one another, and wherein saidbody has two opposing faces defined by closed curved portions of saidbundles,

(c) interconnecting at least a major proportion of said filamentarystructures at a plurality of spaced points along their lengthsthroughout the three dimensions of said body while maintained insinusoidal configuration, and

(d) sectioning the body in a plane intermediate said two opposing faces.7

2. Method according to claim 1 wherein the interconnecting of saidfilamentary structures is effected by means of a binder composition.

3. Method according to claim 2 wherein said binder composition isprovided in an amount of at least about 0.5% based on the weight of saidfilamentary structures.

References Cited by the Examiner UNITED STATES PATENTS 1,785,937 12/1930Curtis 15672 X 1,842,746 10/1932 Chance 156--254 X 1,864,478 6/1932 Ward156-265 X 2,639,250 5/1953 Reinhardt 156---66 3,085,922 4/1963 Koller161--67 3,173,823 3/1965 Guinard 156-435 EARL M. BERGERT, PrimaryExaminer.

HAROLD ANSHER, Examiner.

1. METHOD FOR THE PRODUCTION OF A POROUS SELF-SUPPORTING SHEET MATERIALCOMPRISING (A) PROVIDING ONE OR MORE FIBROUS BUNDLES EACH COMPOSED OF APLURALITY OF CONTORTED FILAMENTARY STRUCTURES WHICH ARE OVERLAPPING ANDINTERCONTACTING THROUGHOUT THE THREE DIMENSIONS OF THE BUNDLE, SAIDFILAMENTARY STRUCTURES BEING ALIGNED GENERALLY IN THE SAME DIRECTIONTHROUGHOUT THE BUNDLE, (B) PLEATING SAID BUNDLES IN SIUSOIDALCONFIGURATION TO PROVIDE A BODY HAVING A FIBER DENSITY BELOW 25LBS./FT.3, WHEREIN FILAMENTARY STRUCTURES OF ADJACENT PLEATS OF THEBUNDLES OVERLAP ONE AOTHER, AND WHEREIN SAID BODY HAS TWO OPPOSING FACESDEFINED BY CLOSED CURVED PORTIONS OF SAID BUNDLES,